html, body{
    height: 100%;
    width: 100%;
    padding: 0;
    margin: 0;
    background-color: #212121;
}
iframe{
    height: 100%;
    width: 99.7%;
    padding: 0;
    margin: 0;
}

.header {
    position: absolute;
    background-color: #212121;
    width: 100%;
    height: 5%;
    z-index: 2;
}

.left {
    position: absolute;
    top: 5%;
    width: 250px;
    height: 90%;
    z-index: 1;
}

.content {
    height: 95%;
    box-sizing: border-box;
    border-left: 250px solid transparent;
    border-top: 35px solid transparent;
}
.bottom {
    position: absolute;
    background-color: #181818;
    width: 100%;
    height: 5%;
}